US437077A - Lifting-jack - Google Patents

Description

(No Model.)

J. W} ALFRED. LIFTING JACK.

No. 437,077; Patented Sept. 23 1890.

IIIIIIH To all whom it may concern:

UNITED STATES PATENT Orricni JAMES W. ALFRED, OF LEWISTOX VN, PENNSYLVANIA.

LlFTlNG-JACK.

- SPECIFICATION forming part of Letters-Patent No. 437,07'i', dated September 23, 1890.

Application filed March 4, 1890. Serial No. 342, (N 111 Be it known that I, JAMES IV. ALFRED, a citizen of the United States, residing at Lewistown, in the county of Mifilin and State of Pennsylvania,have invented certain new and useful Improvements in Lifting-Jacks; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to certain new and useful improvements in lifting-jacks; and it has for its object to simplify and cheapen the construction, and at the same time to render more efficient in operation this class of appliances.

To these ends and to such others as the invention may pertain, the same consists in the peculiar construction and in the novel combination, arrangement, and adaptation of parts, all as more fully hereinafter described, shown in 'the accompanying drawings, and then specifically defined in the appended claims.

The invention is clearly illustrated in the accompanying drawings, which, with the letters of reference markedthereon, form a part of this specification, like letters of reference indicating like parts throughout the several views, and in which- Figure 1 is a side view of a lifting-jack constructed in accordance with my invention. Fig. 2 is an edge view of the same. Fig. 3 is atransverse section upon the line a; {B of Fig. 1. Fig. 4is an enlarged sectional detail showing the arrangement and operation of the levers. Fig. 5 is a section upon line y y of Fig. 4.

Reference now being had to the details of the drawings by letter, A represents the standard, which is made of cast-iron and is provided with a suitable base portion A, said base portion being cast integral with the standard and may be of any convenient or desired size or form.

The standard A is provided with a central longitudinal opening B, extending throughout the entire length, said central opening being preferably rectangular in cross-section,

and within this opening is placed the lifting bar 0, which is provided at its upper end with a bearing-block O, and at its lower end a horizontal lug or extension 0 is provided, which lug is adapted to project through a vertical slot 0 provided for the purpose in the rear face of the standard, said slot extending from the extreme lower end of the standard upward to a point slightly below the point at which the operating handle or lever is pivoted upon the opposite side of the jack. The vertical face of the lifting-bar 0 upon the side opposite to that which is provided with the 6 5 lug (3 is provided with a series of notches, thus forming a rack-bar 0 with the notches of which the latches hereinafter described for moving and regulating the movements of the said lifting-bar engage in operating the device.

D is a casting which forms the inner end of the operating-lever. This casting is provided atone of its ends with a socket to receive the handle-bar D, and at its opposite end is pro- 'vided with a circular drum or shaft D the length of said shaft being such as to adapt it to be fitted within a vertical recess D providedin the front face of the extension D in the upper portion of the standard. The arm or casting D, carrying at its inner end the shaft or drum D is pivotally connected with the jack by means of a piv0tD ,passed through the enlarged portion D of the upper portion of the jack and passing through the drum D at the point at which said drum unites with the body of the casting D. The drum D is provided with a central peripheral groove D and within this groove is loosely seated the bifurcated lower portion of the latch E, the 0 arms E of which bifurcated portion of the latch are curved, so as to conform to the curvature of the drum. The free end of the latch E is adapted to normally rest within the notches in the face of the rack-bar 0 this connection I desire to call particular attention to the form of the latch E and its connection with the drum, and. also to the pointat which the said drum is pivoted with reference to the body of the latch, as in the peculiar Ioo construction and arrangement of theseparts resides an essential feature of the present invention. It will be observed upon reference to the drawings that the body of the latch E is heavy, and that when in position it is slightly inclined from a vertical position. This inclination, although slight, should at the same time be suflicient to insure the latch being at all times normally held in position by gravity. The pivotal point of the drum D is adjacent to its periphery upon the side of the drum which is opposite to the body of the latch, and the center of the pivotal point of the drum should be upon aline drawn through the center of the drum and extended through the free end of the latch. It will be seen at once that the greatest possible amount of power is obtained by this construction, as the lifting force is exerted in a direct line from the pivotal center to the point at which the power is imparted to the rack-bar.

G is a supplementary latch or follower, which is pivoted within the vertical recess in the front face of the standard, at a point slightly above the latch E. This latch G is provided with a longitudinal transverse recess G, through which recess is passed a pin or shaft G said pin extending through the side wall of the jack and being provided with a suitable operating handle or button G by means of which the pin may be moved vertically within a vertical slot G thus permitting the operator to raise the latch G from its engagement with the notches in the rack-bar,

when desired.

The latch E is provided upon one of its side faces with an extending lug or pin H, and beneath this pin or lug is pivoted a small latch H Said latch H is carried upon the inner end of the pivot H the opposite end of which pivot is provided with a suitable operating button or handle, by turning which the said latch E may be disengaged from its connection with the teeth of the rack-bar, as will be readily understood.

It'will be observed that by the construction above described, in whatever position the operating-handle may be placed the vertical aperture in the face of the jack within which the inner end of the handle is pivoted will at all times be closed, thus preventing possible accumulation of dust or dirt within the interior of the jack, which might in time interfere with the working of the several parts.

The operation of the device is simple and will be readily understood in connection with the foregoing description of construction.

J is a handle by means of which the jack may be raised or carried about, when desired.

Having thus described my invention, what I claim to be new, and desire to secure by Letters Patent, is'

1. The combination, with the standard, the lifting-bar having a rack thereon, the operating-lever, the drum or shaft carried thereby, said drum being provided with a peripheral groove, a latch having bifurcated arms adapted to engage the groove upon the drum, and a body portion adapted to engage the rackbar upon the lifting-bar, and a supplemental latch H beneath the actuating-latch, said latch H being adapted, when turned by means of a connecting-handle upon the outer face of the jack, to release the actuating-latch from its engagement with the rack-bar, substantially as and for the purpose specified.

2. In a lifting-jack, the combination of an operating-lever having at its pivoted end an eccentric bearing-surface, a latch having its bifurcated lower end embracing said eccentric bearing-surface and its upper end adapted to engage the notches upon the side of the lifting-bar, the whole being so arranged that when the cam is at the extreme limit of its throw the center of the pivot of the lever, the extreme point of the cam, and the opposite end of the latch shall be in a straight line, substantially as and for the purpose specified.

In testimony whereof I aflix my signature in presence of two Witnesses.

JAMES W. ALFRED.

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